1. Field of the Invention
The present invention relates to a lighting device and specifically to a portable lighting device, that is miniaturized, light weight and easy to carry. The invention particularly relates to a portable lighting device which can be attached to key, a tool, a pen or the like.
The locking/unlocking device according to the present invention is also directed to a system in which a door, a safe, a lock or the like (all are generally referred to as "a lock" in the present invention) is opened or closed safely and correctly according to the both the operation of a key, a card, or the like, (these are generally referred to as "a key" in the present invention), and according to a predetermined light signal.
2. Background Art
Heretofore, a holder of the intended type mainly has been used as a key holder. Accordingly, a conventional key holder will be described hereunder as an example of the holder.
Generally, with respect to a conventional key holder, a holder body and a key are connected to a cylindrical ring or to a chain through a necessary setting member or clamp. Accordingly, the conventional key holder has a disadvantage of being bulky to carry about and, particularly, it becomes more bulky to carry about as the number of keys increases.
Furthermore, in the case where locking and unlocking is to be performed by the use of a key in a poor visibility condition, for example, at night or in a dark place, it is necessary to hold a lighting device with one hand and at the same time handle the key with the other hand because the conventional key holder, as well as the key, has no lighting device. Accordingly, the conventional key holder has a disadvantage of being inconvenient to handle. Moreover, a so-called flashlight has been mainly used as the conventional lighting device. However, the flash light has a disadvantage of poor visibility in lighting a limited small area such as a keyhole while it nonetheless has the advantage of being able to light a wide area.
Heretofore, in the case of a key carrier, the key has been mounted to a chain-like member or the like connected to a key holder body and the key has not been directly united or connected to the body forming the object to be held of the key holder. In this case, no problem worthy of mention has arisen with respect to the carrying of the key. However, when the key is used under poor visibility condition such as darkness, there has been the inconvenience of searching for a keyhole by feeling. However, a key holder capable of lighting a keyhole has been proposed. In the proposed illuminating key holder, however, the illuminating key holder has been integrally fixed to the key. Therefore, it has been necessary to make two operations for illumination and for turning the key requiring two hands in the troublesome manner.
With further industrial development and with the increase in the standard of living the use of locks or the like has increased. As a result, it has become common for a person to carry a number of keys, cards, or the like. Accordingly, a key is often dropped or lost, and the key itself is often stolen, so that the key can be used by another person to the detriment of the owner. Accordingly, the conventional locking/unlocking devices have been disadvantageous even in view of its intended safety. At present there is no provision for making it difficult to open a lock with a key found or stolen by another person.